What's it worth?

[Whitie]

I'm seriously considering buying this 1987 C30 Silverado and looking go get some opinions on what you guys in the know think it's worth.
Long story short, 2 owners. Current owner is in his 60's and has owned it since 94. 102k on odo, and he bought it with 68k. Right before he bought it, it had the motor & tranny re-built and vastly improved (zero emissions crap). 454ci, .030 over, lumpy cam (not sure what size), Holley 850 carb., Doug Thorley headers, plus countless other upgrades. Dyno'd at over 400hp. It also has an 8' Fisher Minute Mount plow that comes with it, which he bought new in 94, and he literally used less than 10 times to plow his driveway. I've known him and the truck for better than 20 years, and it is tight as a drum. He pulls his race car trailer back and fourth to Epping NH dragway about 6 times a year (185 mi. round trip), and sails along at 75mph+ like a dream. Garage kept, rarely used, and not his daily driver by a longshot! It's never been offroad, beat on, or abused in any way (this guy is ANAL! ) The ONLY problem is the surface rust just starting around the fender flares on the bed (no holes), the cab is PERFECT! The truck has ZERO rattles, shimmeys, leaks, squeaks, or funny noises at all. Everything works, and it needs NOTHING!

Soooo.... what do ya think it worth? (retail?)

Thanks in advance everybody!